1. Field of the Invention
The present invention relates generally to dental and orthopedic diagnosis and treatment, and in particular to a densitometry modeling system and method.
2. Description of the Related Art
The field of dental diagnostics is generally concerned with locating pathologies in the dental structure, i.e. the teeth and surrounding tissue and bone. Three of the most common pathologies are: 1) caries associated with decay; 2) fractures; and 3) apical abscesses. The system and method of the present invention are primarily, but not exclusively, concerned with detecting these pathologies and with orthopedics.
Early detection of dental pathologies is very important in minimizing damage. Conventional diagnosis procedures are generally performed using dental X-rays (both fixed beam and scanning beam), explorers, and other conventional equipment.
Incipient caries, particularly those located beneath the enamel surface, often go undetected with conventional equipment. When such caries are finally found, considerable damage to tooth structure may have already occurred. Subsurface, incipient caries are located almost entirely within the enamel layer of the teeth. They are sometimes referred to as xe2x80x9csmooth surfacexe2x80x9d caries and are particularly difficult to locate using conventional diagnostic equipment and procedures. By the time such incipient caries are located, the extent of the damage is often 17% to 23% greater than it would appear to be on a conventional X-ray negative.
Dental fractures can result from bruxism (teeth grinding), trauma, etc. Dental structure which is weakened by various causes, such as decalcification, is particularly susceptible to fractures. Fractures can assume various configurations, including craize line patterns. Fracture patterns and configurations can be particularly difficult to locate using conventional X-ray equipment and procedures. For example, fractures which are generally parallel to the X-ray beam are often undetectable on an X-ray negative. Undetected, and hence untreated, fractures can provide direct paths through the enamel layer of the teeth whereby bacteria can invade the dentin and pulp layers. Pathologies in the dentin and pulp layers are often associated with considerable pain and tooth loss.
Apical abscesses comprise yet another dental condition which can be difficult to diagnose with conventional equipment, particularly in the early stages. Advanced apical abscesses can cause considerable pain because they involve the neurovascular bundles located in the root canals. Early detection of apical abscesses can lead to appropriate, early-stage treatment, thus avoiding advanced disease processes with resultant pain, swelling, and/or space involvement which left untreated could ultimately result in death.
Tomography or sectional radiography techniques using scanning X-ray beams have previously been employed for dental applications. For example, U.S. Pat. No. 4,188,537; U.S. Pat. No. 4,259,583; U.S. Pat. No. 4,823,369; U.S. Pat. No. 4,856,038; and U.S. Pat. No. 5,214,686 all relate to dental X-ray diagnosis utilizing scanning techniques and are incorporated herein by reference.
In the medical field, densitometry procedures are used for measuring bone morphology density (BMD) by utilizing scanning X-ray beam techniques. Examples are shown in U.S. Pat. No. 5,533,080; U.S. Pat. No. 5,838,765; and U.S. Pat. No. Re. 36,162, which are incorporated herein by reference. Medical applications of densitometry include the diagnosis and treatment of such bone diseases as osteoporosis.
The availability of relatively fast computers with large memories at reasonable costs has led to the digitalization of X-ray images for mapping BMD models in various formats. For example, BMD images use color to identify varying densities. Digital BMD patient models are also used for comparison purposes with standard models and with patients"" own prior BMD histories. Age correction factors can be applied to patients"" models for diagnosing and monitoring the onset and progress of such medical conditions as osteoporosis and the like. The present invention utilizes such densitometry modeling and mapping techniques for dental applications.
In addition to pathology detection and diagnosis, the present invention has applications in monitoring osseointegration. Osseointegration occurs at the interface between bone structures and prostheses, such as implants and replacement joints. For example, dental implants osseointegrate with patients"" dental structure. The application of tomographical densitometry techniques to osseointegration monitoring can provide the dental or medical practitioner with important information in evaluating the effectiveness of implant procedures.
Heretofore there has not been available a system or method for applying the technology of densitometry to dental and medical applications such as the detection of caries and decalcification and the monitoring of osseointegration in connection with dental and medical prostheses.
In the practice of the present invention, a dental and orthopedic densitometry modeling system utilizes a controller with a microprocessor and memory. An input device inputs data to the microprocessor for controlling the operation of the modeling system and for providing a database including densitometry parameters for comparison with a patient""s densitometry model. The controller controls the operation of X-ray equipment, which is adapted for scanning patients"" dental and orthopedic structures along preprogrammed scan paths. The X-ray output is processed by the microprocessor for creating a densitometry model, which can be output in various formats. In the practice of the method of the present invention, a patient and the X-ray equipment are positioned relative to each other. A controller is preprogrammed with a scan path and with data corresponding to the patient. The X-ray equipment emits and detects X-ray beams at first and second energy levels to provide densitometry output. The densitometry output is digitized and merged to provide a tomographic model, which can be compared to predetermined parameters unique to the patient. The model can be output in various formats, including a visual image color-coded to depict varying dental and orthopedic structure densities.
The principle objects and advantages of the present invention include: providing a dental and orthopedic diagnostic application for densitometry; providing such an application which includes a method for modeling dental and orthopedic structure using densitometry; providing such a method which includes dual-energy, X-ray emission and detection; providing such a method which includes providing a color-coded output model showing dental density; providing such a method which detects incipient caries; providing such a method which is adapted for detecting decalcification beneath the surface of the dental enamel layer; providing such a method which employs scanning X-ray techniques; providing such a method which utilizes commercially available tomography equipment; providing such a method which detects dental fractures; providing such a method which detects dental apical abscesses; providing such a method which detects dental pathologies at the micron level; providing such a method which facilitates the monitoring of decalcification in dental structures for determining appropriate treatment; providing such a method which is adaptable for monitoring osseointegration; providing such a method which can be practiced with relatively minor changes to existing densitometry equipment; and providing such a method which is economical in operation and particularly well adapted for the proposed usage thereof.